That also means no /dev/kmem etc., and on top of that POSIX file permissions are by far not the only thing that is protecting access to the file system.
If you want to go down the rabbit hole: https://help.apple.com/pdf/security/en_US/apple-platform-sec...
SIP is a good compromise: it prevents malware from gaining completely control of the system but someone with physical access and administrator privileges can disable it for the few situations where that's desirable. That's not a high bar when you need it but it probably has a 100000:1 ratio of time preventing someone's day from getting worse to actually preventing legitimate work.
(It doesn’t have nearly enough security yet, but it’s much more advanced than Linux. And strangely also OpenBSD, who like defending against imaginary attackers doing imaginary attacks instead of their real weak points.)
A couple years ago many edit houses in LA suddenly had boot issues because a Chrome update was over writing system files when the updater was run with elevated privileges.
The issue was that these studios used Avid which required disabling sip at the time.
Other houses that didn’t disable sip were unaffected because it protects against exactly this kind of scenario.
Disabling it is ok but the problem with that is that you lose all security. There should be a way to add our own signing keys to persist changes to the SSV (Signed System Volume) and SIP protected folders. It shouldn't be trust only Apple or nothing.
That is actually how it is in reality, and maps very well to as analogies go to GM the two levels of SIP.
[1] https://www.freebsd.org/cgi/man.cgi?query=securelevel&apropo...
You can't disable SIP on a live system and you can't automate actions in recovery mode.